Impact of Metabolic Syndrome on Left Ventricular Deformation and Myocardial Energetic Efficiency Compared Between Women and Men: An MRI Study.

Abstract

Metabolic and hemodynamic alterations in metabolic syndrome (MetS) can cause a reduced myocardial energetic efficiency (MEE). Indexed MEE (MEEi), as a simple estimate of MEE, is emerging as a novel and useful imaging parameter. To investigate the impact of MetS on MEE and systolic myocardial strain and to assess any sex difference. Retrospective. A total of 161 patients with MetS (female: n=82, 52.2 ± 11.7 years; male: n=79, 51.8 ± 10.6 years) and 77 healthy subjects (female: n=46, 52.7 ± 8.2 years; male: n=31, 54.1 ± 11.2 years). Patients with left ventricular (LV) ejection fraction <50% were excluded. A 3.0 T; balanced steady-state free precession sequence. LV volumes and mass (LVM) and global longitudinal strain (GLS) were obtained by MRI. Stroke volume (SV) divided by HR was used as a surrogate measure of MEE and normalized to LVM (MEEi). Student's t-test or Mann-Whitney U-test; Multivariable linear regression (coefficient of determination, R2 ). P < 0.05 was considered statistically significant. For both males and females, MEEi and GLS were lower in MetS patients than in the normal controls. Among MetS patients, men had significantly higher LVM (59.7 ± 13.4g/m2 vs. 48.8 ± 11.3g/m2 ) and significantly lower MEEi (0.68 ± 0.23 mL/g/s vs. 0.84 ± 0.23 mL/g/s) and GLS (-11.7% ± 2.8% vs. -13.9% ± 2.7%) than women. After adjustment for clinical variables, male gender (β=-0.291) was found to be inversely correlated with MEEi. Multivariable analysis showed that MEEi (β=0.454) were independently associated with GLS (adjusted R2 =0.454) after adjustment for clinical and other MRI parameters. MEEi was significantly impaired in MetS without overt systolic dysfunction. There was a sex difference regarding the cardiac alterations in MetS, with men having significantly lower MEEi and GLS and significantly higher LVM than women. Further, MEEi was independently associated with GLS. 3 TECHNICAL EFFICACY: Stage 3.